Endomembrane System
Chinar, Rajesvari, Natalie
Endomembrane System
● A set of membranes which are found inside
and around a eukaryotic cell
● They are related by direct contact or transfer
through vesicles
Structures
Structures
● Nucleus - structure that contains genes
● Nuclear Envelope - structure around the nucleus that
●
●
separates the membranes from the cytoplasm
Endoplasmic Reticulum (ER) - complex network or
membranes that makes up over half the eukaryotic cell
○ Smooth ER
○ Rough ER
○ Transitional ER
○ ER Lumen
Golgi Apparatus - The cells warehouse, an area of
manufacturing, sorting, and shipping. Proteins are
modified, from a stored then sent to other destinations.
○ Cisternae Golgi (cis)
○ Transport Golgi (trans)
Functions of Smooth ER
Major:
● According to the cell it goes through
different metabolic processes which may
include:
○ Synthesis of Lipids
○ Metabolism of Carbohydrates
○ Detoxification of Drugs or Poisons
Minor:
● Stores Calcium Ions
Functions of the Rough ER
Major:
● Helps secrete proteins (glycoproteins)
and hormones into the bloodstream
(transports vesicles)
○ Ex) Pancreatic Cells to make insulin
Minor:
● Membrane Factory - grows while adding
membrane proteins and phospholipids
Rough & Smooth ER
Functions of cis Golgi
● flat membranes which are sac-like
● each cell may have 100 stacks
● cis face- receives proteins
Functions of trans Golgi
● transports vesicles
● moves material from the ER to the Golgi
Apparatus
● trans face: transcends vesicles which break
off to go to other sites
cis & trans Golgi
Where are they found?
● The endomembrane is found in general
eukaryotic cells, such as plants and animals.
Interaction
● Nuclear envelope is connected to the rough
ER which continues with the smooth ER
● Proteins that are made in the ER flow from
the transport vesicles to the Golgi
● Golgi breaks off while transporting vesicles
that give rise to lysosomes, which is available
for fusion with other vesicles
● then transport vesicles carry proteins to the
plasma membrane